Aseptic packaging is widely used to prolong the shelf life of food and drink products. With conventional aseptic packaging, the product is filled and sealed in the package under sterile or bacteria-free conditions. Aseptic packaged food and drink products work in conjunction with a dispensing apparatus constrained by the requirements that the system deliver sterile product at the point of use and be cost effective. The shelf-life of aseptically packaged product after opening is re-contamination. The dispensing path of an aseptic package, culminating in a one-way valve, creates an avenue whereby re-contamination can occur and has been the subject of improvement efforts.
One-way valves used in conjunction with aseptic packaging can be classified as those integral to the dispensing apparatus, those comprised of parts integral to the dispensing apparatus and other parts integral to the aseptic packaging, and those integral to the aseptic package. These different one-way valve choices influence the duration of time between opening and product re-contamination, the cost of packaging, and the requirement for product refrigeration.
A dispensing apparatus with an integral one-way valve has the risk of product re-contamination in the connection of the aseptic package to the one-way valve. Absent effective cleaning the life of the product may be considerably lowered due to contamination at the point of connection from the dispensing apparatus to the aseptic package. One effort to address this problem in the prior art is U.S. Pat. No. 6,024,252 where the dispensing apparatus includes integral pinchers to open and close an open-ended, flexible tube connected to the pouch for dispensing product therethrough. The one-way valve closes the tube from the ambient atmosphere by pinching the open end of the tube. In order to dispense product, the pinch valve is released from the tube, and the product is in turn allowed to flow from the pouch and through the open end of the tube. One of the drawbacks of this type of prior art dispenser and packaging is that during installation of the pouch and tube assembly into the dispenser, and during dispensing, there is a risk that bacteria or other unwanted substances can enter into the open ended tube and contaminate the product. If the product is a non-acid product, such as a milk-based product, it must be maintained under refrigeration to ensure the life of the product.
One-way valves integral to an aseptic package address the problem of re-contamination at the connection interface between the aseptic package and the dispensing apparatus through removing the interface, limiting this class of one-way valves to re-contamination solely through the outlet of the one-way valve itself. U.S. Pat. No. 7,322,491 further addresses this problem through advantageous use of a valve-seat, valve-cover combination to hermetically seal the product in the package throughout its shelf life and multiple dispensing of the product. Such a one-way valve allows for the use of non-acid products, such as milk-based products, without refrigeration. Such a one-way valve also creates the need for integration into a dispensing apparatus and the challenges thereby imposed.
Aseptic packaged materials face the problem of contamination upon exit from the package. Sources of contamination include residual material from previous operation of the valve, micro-organism contamination, and contamination introduced to the outlet face of the one-way valve during assembly or cleaning of the dispensing apparatus. A remedy known in the art includes the incorporation of clean-in-place functionality. Clean-in-place functionality institutes periodic cleaning of food contact surfaces by introducing a cleaning fluid like water, soap, bleach, or a like material or combination of materials to the surfaces. The surface then is exposed to an atmospheric change that includes elevated temperature or pressure change. The result of the process is to substantially remove material that would otherwise be positioned to contaminate product subsequently crossing the one-way valve.
Such clean-in-place functionality imposes the constraint that the cleaning fluid not break the hermetic seal between the space being cleaned and the product reservoir. Further, if a one-way valve is used in connection with such clean-in-place functionality, the one-way valve must resist the pressure of fluid used by the clean-in-place functionality so as to prevent the introduction of contaminates into the one-way valve. Additionally, such one-way valves need to maintain their hermetic seal when a temperature gradient is imposed across the one-way valve by the clean-in-place fluid contacting the exterior surface of the one-way valve. Such one-way valves need to not distort or change shape so as to pass a different amount of material in response to a given product pressure as a result of having been subjected to a series of clean-in-place cycles. Finally, such one-way valves need to maintain their hermetic seal when clean-in-place functionality includes the application of a vacuum to the surface of the one-way valve.
Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks and/or disadvantages of the prior art.